Sulkies are very light carriages which are used in trotting races, where the driver sits on a very light-weight two-wheeled carriage. The driver therefore sits with his centre of gravity over and slightly behind the wheel mounting, with the result that when he swings or stretches his legs, this causes a kind of up and down rocking movement, thus influencing the horse. Impulses of this kind are intended to give the horse added inspiration, thus contributing to the attainment of maximum speed.
From DE-A-3 313 694 (corresponding to SE-B-449 202) it is known a sulky construction with shafts which are provided with arm members extending downwardly from each shaft. The shaft itself extends to the beam section of the sulky, so that the main function of the arm members extending downwardly in direction to the wheels is to be supporting elements. After having made all adjustments necessary for using the sulky the arm members will maily act as a stiff connection. In the known embodiment it is in the lower part no pivotal connection to the rear part of the shaft. By the construction according to the German publication it is an object with simple means being able to displace the wheels in the length direction of the sulky. The sulky has therefore been provided with a wheel mounting which makes it possible to displace the position of the wheels in the length direction of the sulky in order to control and change the vertical load on the wheels according to the hardness of the road, without having to change wheels. In order to reduce the rolling, friction on the soft tracks the wheels should be positioned more backwardly in relation to the driving direction. Such a change of the positioning of the wheels will have influence on the forces exerted on the horse in the direction vertical to the direction of movement, it is, however, not achieved any forces on the horse in the moving direction, i.e. no horisontal forces are established.
Even though a swinging movement of this kind will influence the horse, it will only exert an up and down momentum on the horse and due to the rigid design of the sulky this will also cause relatively hard jolting movements.